Process of separating zinc and lead from mixed sulfids.



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" O; A. L. W. WITTER.

PROCESS OF SEPABATING zmo AND LEAD FROM MIXED SULFIDS. APPLIUATIDNiILED, NOV. 8, 1909.

1,04 '7 ,3 0, 1 Patentd Dec. 17,1912.

applied in uncivilized UNITED sTArEs PATENT OFFICE.

CARL AUGUST LOUIS WILHELM WITTE It, 015 HAMBURG, GERMANY.

' PROCESS OF SEPABATING ZINC AND LEAD FROM MIXED SULFIDS.

Patented Dec.1'7,1912.

Application filed November 8, 1909. Serial No. 526,827.

To all whom it may concern:

Be it known that I, CARL AUGUST LOUIS WILHELM Wrrrnn, a citizen andresident of Hamburg, Germany, have invented a certain new and usefulProcess of Separating Zinc and Lead from Mixed Sulfids, of which thefollowing is'a specification.

The present invention relates to an improved process of separating zincand lead from mixed sulfids.

The'problem of the rational treatment of ores containing a mixture oflead and zincthe so-called complex sulfids-has not yet been solved,notwithstanding the extraordinary amount of money and labor sacrificedsince the celebrated Broken Hill mines in Australia were discovered. Inmany cases where such complex ores occur it has been possible to utilizethem by applying new working processes, but in other cases every knownprocess has proved unsuitable. A considerable number of endeavors tosolve this problem are recorded in patent literature but very few .ofthese have gone beyond the experimental stage, and of these few only onehere and there has been put into practice with more or less success. Theprocess hereinafter described can be used for the treatment of any mixedzinclead ore that occurs in nature, and it can be lands provided onlythat coal or wood, or water power, is available.

The new process aims at the complete separation of the zinc from thelead and from the precious metals contained in ore at one operation. Itis based upon the well known fact that lead and zinc can be almostcompletely separated if their oxids be mixed with the quantity of coalrequired to reduce them, and the mixture exposed, in a suitable neutralor reducing atmosphere.

The new process is carried out by means of .a reverberatory furnacewhich I have illustrated, by way of example, in the accompanying sheetof'drawings in which- Figure 1 is a longitudinal sectional elevation andFig. 2 a plan of the reverberatory furnace; Fig. 3 is across section ofthe said furnace.

Similar letters of reference refer to like parts throughout the figures.

- a is the hearth, b the arch, c are the gas ports, d the chargingshafts, e is the layer of slag, f the slag outlet, 9 the tap for drawingofi thelead, h the flue or uptake 'at the head of the furnace.

The'new process is carried out as follows:

The sulfid ores are ground so as to reduce them to a degree of finenessthat will permit of proper roasting or calcination. They are thenroasted till they contain only traces of sulfur and are mixed with thenecessary quantity of reducing material, for example coal, and with somebinding material such as lime, and formed into briquets. These briquetsare fed through the charging or filling shafts d into the reverberatoryfurnace that is with producer gas, or some other gas, or electrically.In order to maintain a nonoxidizing, that is to say, a neutral, orpreferably, a reducing atmosphere, at the part where the furnace ischarged, the gas and air must be introduced as it is the case with thegas ports 0, at or near the arch of the furnace and inasmuch as theflame is drawn toward the flue .by the draft the whole process soconducted that the products of combustion do not come into contact withthe material charged, nor pass through the material that is being putin. A layer of fluid slag e is constantly kept in the furnace. This slagmay if required be matte or metal and it serves as an under lay for thenew material 71 introduced into the furnace, which floats upon it. Theunderlay is permeable by the reduced lead or the matte that is formed.The layer of slag or matte in the furnace must be so thick as to preventany large variation of temperature when a new charge is introduced. Theintroduction of the charge is effected through the said filling shafts dat the sides of the top of the arch, in such a manner that the chargingof the furnace takes place at a point back of or at the rear end of thecur rent of gases and air passing to the flue i. e., The shafts areconstantly kept filled with fresh briquets and flux and kept closed.

The furnace works continuously. As the briquets disappear, fresh ones,along with the necessary flux, fall from the filling shafts, in whichthey have been pro-heated. The reduced zinc is volatilized and in theflue or uptake it meets the combustion gases and atmospheric airadmitted into the flue replaced by heated through the gas portsc awhereby the furnace as an oxid, practically free from lead. When thegases are. cooled, the oxid is recovered by condensation? The residueleft in the furnace is skeletonlike and contains the reduced lead in theform of small globules. On coming in contact with the fluid slag, thegangue of the oreis taken up by it, and the metallic lead sinks to thebotpasses gradually,

tom. Any excess of coal alon with the slag, toward theslagj outlet f, beow the uptake or flue h, and as it moves it spreads itself over the slagand is burned. The slag is drawn ofl" eriodically.

The results gotten by the application of the-process above described areattained because the charge put into the furnacedoes I not come intocontact with the gases coness into practice is not restricted to thestate such .as

use of coal as a reducing means, an addition for example, of metalliciron may also serve the purpose. This metallic iron addition reacts onthe zinc 0nd or other zinc combinations setting free at the same timemetallic zinc. The latter escapes with and is re-oxidized by thecombustion gases and admitted atmospheric air into zinc oxid, as alreadystated above.

Instead of iron alone a mixture of iron and coal or iron oreand coal maybe used as areducing means. Instead of working materials in a solidstate materials in a fluid previously molten ores, fluidslags of leadandcopper-furnac'es, and the like may be used. A corresponding quantity ofsuch fluid material is mixed with iron or spongy iron obtained byreducing iron ore or the like and the mlxture subjected to a furtherheating in tory fur'nace,'the sole or bottom of which is constituted bya layer of slag of a suflicient thickness or depth in order to preventany greater variations of temperature when introducing new charges.

's process isdistinguished from the al ready known purely metallurgicalprocesses by the fact that in the latter there are always mixed with thezinc oxid considerable quantities of lead, if not all the lead, in theform of lead oxid.

I claim:

1. The process of separating zinc and lead from mixed sulfid ores in asuitable furnace, which comprises simultaneously reducing the oxidizedoresand separating its is re-oxidized, and issues from slag; andbecause, after all lead, which com presence of a non-ox1 therebyvolatilizing the down and slagging the residue and recoverthe reverberathe metals in a non-oxidizing atmosphere substantially out ofcontactwith the flame at a. suitable reducing temperature while maintaining alayer of slag sufliciently thick to insure regulation and uniformity oftemperature and under whichsubstantially all of the. lead collects.

2. The process of, separating zinc and lead from which comprisescharging the oxidized ore into a suitable furnace with duction andseparation of the metals in a non-oxidizing atmosphere at asuitable'reducing temperature and. substantially out of contact with theflame of the furnace while maintaining a layer of slag suflicientlythick to insure regulation and uniformity of temperature.

3. The process of separating zinc and mixed ores ofzinc and lead,"

a reducing agent, and simultaneously efl'ecting the relead from' mixedores of zinc and lead,

which comprises charging the ore with car bonaceous material and amaterial contain-' ing iron into a suitable furnace, and simultaneouslyeffecting the separation of the metals in a non-oxidizing atmosphere .ata

'- suitable reducing temperature while substantially out of contact withthe flame of the furnace while maintaining a layer of slag suflicient-lythick to insure regulation and uniformity of temperature.

4. The process of separating zinc and lead from mixed sulfid ores ofzinc and rises oxidizing the ores, charging them with a reducing agentinto a suitable furnace substantially out of contact with the flamethereof on a layer of fluid slag sufliciently thick to insure regulationand uniformity of temperature in the dizing atmosphere, zinc and meltinging the zinc from the furnace gases.

e process of separating zinc and lead from mixed sulfid -'ores of zincand which comprises comminuting the presence of a non-om'dizingatmosphere and substantially out of contact with the flame,

on a fluid slag under lay I uniform temperature within the furnace a ofthe furnace and sufficiently thick to maintain a substantiallytherebyreducmg and evaporating the zinc, oxidizing and cooling the zincvapors, and recovering the zinc as oxid of zinc 6. The process ofseparating zinc and lead from mixed oxidized sulfid ores in a suitablefurnace, which comprises simultaneously reducing and separatin themetals in a reducing atmosphere su stantially out of contact with theflame at a the presence of a substantially quiescent re- 10 ducingatmosphere onto a thick slag underlay, recovering the zinc from thegases and tapping off the lead.

CARL AUGUST LOUIS WILHELM WITTER.

Witnesses:

MAX KAEMPFF. ERNEST H. L. MUMMENHOFF.

